My stairs have a 4 tread winder at the bottom i.e. you enter the stairs facing north and 4 steps later you are facing east. I want to plaster underneath these stairs and want to know what to fix to the stairs to allow me me to do this.

I think i know what you are getting at, if you need the plaster board to "bend" cut thru the back of the board with knife, (not all the way thru just approx 2mm)cut multiple lines where the actual bend in the staircase is, as to fixing the plaster board to the stairs , you may need to fix some 2x1 batons first,failing that give me a call between 0900 & 1600hrs and we will see if we can sort it. Happy boarding HN 07917127751.